Biologic Therapies for Cancer Treatment

Biologic therapies (biotherapy) focus on the body's biological response to the tumor. Most of these therapies take advantage of the body's immune system, either directly or indirectly, to fight cancer or to lessen the side effects that may be caused by some cancer treatments.

How does the immune system work?

How do biologic therapies work?

What are biologic therapies used for?

What are the major types of biologic therapies?

What are the side effects?

How Does the Immune System Work?

In order for cancer to succeed, it must contend with the immune system. The immune system consists of a complex network of cells and organs that work together to defend the body against invaders, like bacteria and viruses.

Enhance the immune system to fight the uncontrolled growth of cancer cells

Make cancer cells more vulnerable to destruction by the immune system

Change the growth patterns of cancer cells so that they are more like normal cells, and are less likely to metastasize (spread)

Block or reverse the process that changes a normal or precancerous cell into a cancerous cell

Enhance the body's ability to repair normal cells that get damaged by other forms of treatment for cancer (eg,
chemotherapy
,
radiation therapy
)

Prevent a cancer cell from spreading to other parts of the body

What Are Biologic Therapies Used for?

Biologic therapies are most commonly used either to treat cancer that does not or has not responded to other forms of treatment or to try to treat tumors that may respond to the body’s own immune defenses.

What Are the Major Types of Biologic Therapies?

The most common biologic therapies include:

Interferons (IFN)

Interleukins (IL)

Colony-stimulating factors (CSF)

Monoclonal antibodies (MOAB)

Interferons

Interferon (IFN) occurs naturally in the body. IFN is produced by virally infected cells and is capable of protecting other cells from infection. There are three major types:

Researchers have found that interferons enhance the immune system’s ability to fight cancer cells and act directly on these cells by slowing growth and encouraging normal cell behavior.

Interleukins

Like interferons, interleukins (IL) occur naturally in the body and can be synthesized in a lab. Interleukins are named numerically: IL-1, IL-2, IL-3, up to IL-18.

IL-2 has been the most widely studied in cancer treatment. This type of interleukin stimulates the growth and activity of many cancer-killing immune cells, including NK cells and cytotoxic T cells. In addition, IL-2 enhances antibody responses.

Colony-stimulating factors (CSFs) do not affect cancer cells directly. Instead, CSFs help stimulate the production of new red blood cells, white blood cells, and platelets. This is important because many cancer treatments can decrease the levels of blood cells, which increases the risk of infection,
anemia
, and bleeding problems. Stimulating blood cell production can help stimulate the immune system.

Some examples of CSFs include:

G-CSF (Neupogen) and GM-CSF (Leukine, Prokine)—increase the number of white blood cells, which reduces the risk of infection; also used to stimulate the production of stem cells in preparation for stem cell or
bone marrow transplants

Oprelvekin (Neumega)—increase the number of platelets and reduce the need for platelet transfusions

Monoclonal Antibodies

Monoclonal antibodies (MOABs) are substances that are produced in a lab. The process involves injecting a mouse with cells for a certain type of human cancer. Once injected with the cancer cells, the mouse produces antibodies to fight against the cancer. These mouse antibodies are then combined with other lab cells to create hybrid cells to fight caner.

MOABs can be used in cancer treatment in a number of ways, for example:

React with certain types of cancer, which may enhance the immune response

Be programmed to act against specific cell growth factors to interfere with the growth of cancer cells

Be linked to anticancer drugs, radioactive substances, other biologic therapies, or other toxins

What Are the Side Effects?

At the beginning of therapy, you will most likely experience flu-like symptoms. Examples include chills, headaches, muscle pain, joint pain, and discomfort.

Chronic side effects tend to increase in intensity after you have been on IFN therapy for several weeks. Loss of appetite with weight loss and fatigue can be severe enough to limit the dose. Other side effects include:

Revision Information

This content is reviewed regularly and is updated when new and relevant evidence is made available. This information is neither intended nor implied to be a substitute for professional medical advice. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with questions regarding a medical condition.

Biologic therapies: using the immune system to treat cancer. National Cancer Institute webite. Available at:
http://www.cancer.gov/cancertopics/factsheet/Therapy/biological
. Accessed September 4, 2012.